Computing units, for example processors, are commercially known that have one or more processor cores and that can access a working memory. In addition, computer systems that have one or more such computing units standardly include a plurality of additional units that work together with the computing unit, such as input/output modules (I/O) and the like. At least some of the stated elements of the computer system can exchange data with one another via a common, preferably parallel, bus. In addition, methods are known for a so-called direct memory access (DMA) whereby the data exchange via the common bus can be improved.